[1][2] During a routine flight from Gander, Newfoundland to Mont-Joli, Quebec, a combination of inclement weather and a mapping error caused the Liberator to collide with the Black Mountain (French: Montagne Noire), killing all those on board.

Jos Gaudet, then on duty in fire tower number four at Archambault lake, did see the light from the burning wreckage on top of the mountain, but thought it was the reflection of the sun on a moist rocky slope.

[2] On the morning of the crash, Gaudet and Georges Moore took a boat around lake Archambault to look for signs of wreckage, such as oil slicks or debris, believing that the aircraft had fallen in the water.

[2][4][6] For almost three years, the disappearance of Liberator Harry remained a mystery, with the most plausible theory explaining failures to locate the aircraft was that it was lying at the bottom of the St. Lawrence River.

Inrig, noticed a glint of sunshine coming from a metallic object and on closer investigation saw the characteristic twin fins of a Liberator near the top of the mountain.

In the afternoon of 3 July 1946, friends and family of the crew and passengers along with many members of the RCAF and religious authorities climbed the mountain to pay their respects to the dead and hold a funeral.

[14] The cenotaph lists on its sides the rank and name of each deceased person and has on its front a pictograph of the ill-fated plane and the following text: En souvenir des vingt-quatre membres de l'Aviation Royale Canadienne qui ont perdu la vie dans l'écrasement du bombardier Liberator Harry sur la Montagne Noire le 20 octobre 1943

In memory of the twenty four members of the Royal Canadian Air Force who lost their lives in the crash of the Liberator Harry bomber on Montagne Noire on 20 October 1943[15]On 15 June 2013, to commemorate the 70th anniversary of the accident, a ceremony was held at the site with military music and flyovers of a CF-18 from the RCAF.

In anticipation of this day and in order to make the site more accessible to less capable hikers, the path to the monument was improved, allowing it to be reached in less than 3 hours by foot from a parking lot at the bottom of the mountain.